Add asyncio.Queue.__iter__()

c8cbe4d0b1a48d31bfaa2dba3f3874c679a02dbe
commit c8cbe4d0b1a48d31bfaa2dba3f3874c679a02dbe
diff --git a/Lib/asyncio/queues.py b/Lib/asyncio/queues.py
@@ -76,6 +76,13 @@ def _wakeup_next(self, waiters):
                 waiter.set_result(None)
                 break
 
+    def __iter__(self):
+        while True:
+            try:
+                yield self.get_nowait()
+            except (QueueEmpty, QueueShutDown):
+                return
+
     def __repr__(self):
         return f'<{type(self).__name__} at {id(self):#x} {self._format()}>'